Field
The present invention relates to an LED lighting device using a ballast
Description of Related Art
Recently, a light emitting diode (LED) is being increasingly used as a new lighting device in place of a filament bulb or a fluorescent lamp and becomes popular. The LED can be driven at a low voltage and has a longer life span, lower power consumption, a more rapid response speed and stronger crashworthiness than those of other lighting devices. The LED can become smaller and lighter. However, since the LED is activated by a very low direct current power and is turned on in a manner different from that of the fluorescent lamp, a general LED lamp cannot be applied as it is to a fluorescent lamp system. In particular, an electronic ballast converts a commercial alternating current power of 60 Hz into a radio frequency of several tens of KHz, and then provides to the lamp. Therefore, conventional lighting devices as well as the ballast should be removed in order to use the LED lighting device. If an LED driving circuit is directly connected to the connection terminal of the conventional ballast without removing the ballast, etc., the LED driving circuit is not able to process the high frequency or voltage of the ballast, etc., so that the LED lamp does not work or is destroyed.
Accordingly, recently, an LED lighting device capable of being directly connected to the ballast and used without removing the ballast is being developed.